welcome to HCM!
I think you injured your abdominal muscles or it may be due to overexercising. Most contusions are minor and heal quickly,but, severe contusions can cause deep tissue damage and can lead to complications .
Sometimes a pool of blood collects within damaged tissue, forming a lump over the injury
)Contusions cause swelling and pain near the injury. The injured muscle may feel weak and stiff. Your hard spot is blood outside any blood vessel and is harmless; your body will absorb this slowly over the next few weeks.
To control pain, bleeding, and inflammation, keep the muscle in a gentle stretch position and Rest
take medications for pain relief.
DO NOT massage
the injured area.